Bradbury's first published story was "Hollerbochen's Dilemma", which appeared in the January 1938 number of Forrest J. Ackerman's fanzine Imagination!. In July 1939, Ackerman gave nineteen-year-old Ray Bradbury the money to head to New York for the First World Science Fiction Convention in New York City, and funded Ray Bradbury's fanzine, titled Futuria Fantasia. Bradbury wrote most of its four issues, each limited to under 100 copies.Between 1940 and 1947, he was a contributor to Rob Wagner's film magazine, Script.
Ray Bradbury was free to start a career in writing when, owing to his bad eyesight, he was rejected admission into the military during World War II. Having been inspired by science fiction heroes like Flash Gordon and Buck Rogers, Bradbury began to publish science fiction stories in fanzines in 1938. Bradbury was invited by Forrest J. Ackerman to attend the Los Angeles Science Fiction Society, which at the time met at Clifton's Cafeteria in downtown Los Angeles. This was where he met the writers Robert A. Heinlein, Emil Petaja, Fredric Brown, Henry Kuttner, Leigh Brackett, and Jack Williamson.
In 1939, Bradbury joined Laraine Day's Wilshire Players Guild where for two years he wrote and acted in several plays. They were, as Bradbury later described, "so incredibly bad" that he gave up playwriting for two decades. Bradbury's first paid piece, "Pendulum," written with Henry Hasse, was published in the pulp magazine Super Science Stories in November 1941, for which he earned $15.
Bradbury sold his first story, "The Lake", for $13.75 at the age of twenty-two. He became a full-time writer by the end of 1942. His first collection of short stories, Dark Carnival, was published in 1947 by Arkham House, a small press in Sauk City, Wisconsin, owned by writer August Derleth. Reviewing Dark Carnival for the New York Herald Tribune, Will Cuppy proclaimed Bradbury "suitable for general consumption" and predicted that he would become a writer of the caliber of British fantasy author John Collier.
After a rejection notice from the pulp Weird Tales, Bradbury submitted "Homecoming" to Mademoiselle which was spotted by a young editorial assistant named Truman Capote. Capote picked the Bradbury manuscript from a slush pile, which led to its publication. Homecoming won a place in The O. Henry Prize Stories of 1947.
It was in UCLA's Powell Library, in a study room with typewriters for rent, that Bradbury wrote his classic story of a book-burning future, The Fireman, which was about 25,000 words long. It was later published at about 50,000 words under the name Fahrenheit 451, for a total cost of $9.80, due to the library's typewriter-rental fees of ten cents per half-hour.
A chance encounter in a Los Angeles bookstore with the British expatriate writer Christopher Isherwood gave Bradbury the opportunity to put The Martian Chronicles into the hands of a respected critic. Isherwood's glowing review followed.